The Ghost Closer (Modeling Air Pressure and Winds)

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Students will be able to model how changes in air pressure can change the weather.

Big Idea

The students suck an egg into a jar and expand a marshmallow in a vacuum chamber in order to model how changes in air pressure can effect the weather!

Introduction and Connection to the NGSS and Common Core

This lesson connects to the following NGSS and Common Core Standards:

MS-ESS2-5  Collect data to provide evidence for how the motions and complex interactions of air masses results in changes in weather conditions.

CCSS.ELA-LITERACY.RST.6-8.1  Cite specific textual evidence to support analysis of science and technical texts.

Science and Engineering Practices:

Developing and Using Models  Develop and/or use a model to generate data to test ideas about phenomena in natural or designed systems, including those representing inputs and outputs, and those at unobservable scales. 

Crosscutting Concepts:

Energy and Matter  

Flows, Cycles, and Conservation: Tracking energy and matter flows, into, out of, and within systems helps one understand their system’s behavior.

  • Matter is conserved because atoms are conserved in physical and chemical processes.
  • Within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter.
  • Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion).
  • The transfer of energy can be tracked as energy flows through a designed or natural system. 

Connecting to the Essential Question: What are you supposed to learn today?

5 minutes

I begin every class by asking the students, "What are you going to learn today?" Students respond by referring to the Essential Question, "How can I demonstrate science and engineering literacy?". This EQ is included on their Unit Plan and on the front board.

As the previous lesson helped students to practice Skill 1 in the Unit Plan, I ask students to reevaluate their self assessments from the previous day. Students rank themselves on each of the skills included in the Unit Plan. Students rank themselves on a scale of 1 to 4 (4 being mastery). Students will continue to update these scores over the course of the unit. I emphasize to them that it is ok not to be at a "4". Learning is about growth! We will use this starting point to track the growth in their learning.

Notice in the student work below, that the student updates his scores over the course of the unit as he grows in his level of mastery.


 Explain that this lesson is focused on Skill 2, "I can create models and collect data to provide evidence for how the motion and interactions of air masses can change the weather."

Mini Lesson: Air Pressure, Wind, and Discussion Protocols

25 minutes

Have the students silently read the Skill W.2 Notes Page that focuses on air pressure. This notes page has many pictures, graphs, and diagrams. Emphasize to students that scientists include this visuals in their writing so that the reader can build a better understanding of the concepts being addressed. If the author chose to put in a diagram, they did so because it is important!  Encourage the students to take time and focus on those pictures/diagrams/graphs as well as their captions.

After students have finished the reading, explain that scientists create models to describe and predict phenomena. Today, they will be creating models that could be used to model air pressure and wind.

Explain that you will model the protocol they will be following for the lesson they will be completing today. First, present them with a simple demonstration that allows them to see air moving from high to low pressure. In my classroom, I do what I call a "Ghost Closer" demonstration. In my classroom I have a door that leads to the outside and a door that leads into the hallway. I say to my students, "This weekend I was working in my classroom with my young daughters. We propped open the door to the outside so that they could go in and out to the courtyard. When we did that, my daughter kept saying, "There is a ghost in the hallway!"  I asked her what she meant and she showed me this." I then open the door to the outside and close the door to the hallway so that it is almost closed, but not latched. Then, I let go. The door opens into the hallway even though there is no one there. I repeat this process acting as if I am my 6 year old daughter amazed that a ghost is opening the door. (Depending on the difference in pressure outside and inside - your 'ghost' may slam the door shut instead of open it.)  I then say, "I'm wondering if there is really a ghost in the hallway."  (But, dont let students offer explanations yet.)

I then pull a group of students to model the protocol they will be following in this lesson. We complete a "Fishbowl Activity" to model this. The students that I choose sit at a table together as if we are in a "fishbowl". The remaining students stand around our table as if they are looking into and observing what is happening inside the "fishbowl".

Provide the students in the "fishbowl" with the protocol and have the students model the discussions for Prompt 1 and Prompt 2.

Prompt 1:

  1. One student presents the prompt to the group by saying, “Models can be used to represent real world phenomena. How could this model a phenomenon that occurs within Earth’s weather systems?”
  2. Have a student time 30 seconds of wait time as the group searches text and considers how this model relates to weather.
  3. One student shares their idea.
  4. Another student summarizes what the group member shared. (The “student that shared” must confirm that the “student that summarized” did summarize what they were trying to say effectively.)
  5. Another student cites text that supports why the example shared could be used to represent the weather element.
  6. Any students with other ideas share their input.

For Prompt 2, I have the whole class join in and follow the protocol together as a whole group.

Prompt 2:

  1. One student presents the second prompt to the group by saying, “Models can be used to make predictions about real world phenomena. Look at the cartoon on the projector What predictions can you make the air pressure and temperature of the air inside and outside of the window based on what was shown in this model?”
  2. Have a student time 30 seconds of wait time as the group searches text and considers how this model could be used to make a prediction.
  3. One student shares their idea.
  4. Another student summarizes what the group member shared.  (The “student that shared” must confirm that the “student that summarized” did summarize what they were trying to say effectively.
  5. Another student cites text that supports why the example shared could be used to predict the direction the wind would be blowing.
  6. Any students with other ideas share their input.

I then explain to students that for the two lab stations they are about to complete, that they will be following the protocols for these same prompts.

I strongly encourage you to follow through with the Fishbowl Activity. Students benefit from watch other students model what the process should look like. The effectiveness of the conversations that will follow in the upcoming lab stations will be elevated by completing this modeling process.

Modeling Air Pressure and Weather Patterns

45 minutes

Students then follow the procedures at two stations. After completing each station, students sit and discuss as they follow the protocol for the two prompts modeled in the mini lesson. The first of each prompt asks students to use the model to represent and describe a weather phenomena. The second prompt asks the students to use the model to help them make a prediction about another situation. Emphasize to the students that they must complete their discussion before moving to the next lab station.

(The NGSS Science and Engineering Practice 2:  Developing and Using Models states that students should be able to develop and/or use a model to predict and/or describe phenomena. These prompts are designed to provide students with practice in these areas.)

**The discussions following the lab stations is where the real learning is going to take place in this lesson. Without effective discussions, students could leave your classroom just thinking, "That was fun!". While having fun is an added bonus, it is important that students take time in the discussions to connect how these stations could connect to weather patterns. As you walk around and listen to discussions, have students connect to the Essential Question and skill that they are focusing on so that they are making the connections they need to reach mastery.

Marshmallow Madness


  1. Draw a face on the marshmallow with a sharpie.
  2. Place the marshmallow in the vacuum chamber.
  3. Turn on the chamber and observe the changes to the marshmallow.
  4. Turn off the chamber and observe the changes to the marshmallow.

Prompt #1:

In this clip, students try to relate the marshmallow model to the text and weather patterns. Notice how students refer directly to the text for evidence and take the time to summarize each other's ideas as they build on each other's responses.

Prompt #2:  

Notice that these students have become familiar with the protocol and end up going "out of order". This is ok!  I want the conversations to flow. As long as they are summarizing each other's ideas and citing text as evidence, they are going to have valuable discussions.


Eggsellent Entry


  1. Put on a pair of goggles.
  2. Place a candle in the top of a hardboiled egg.
  3. Light the candle.
  4. Have one student hold the 1000 mL flask upside down.
  5. Place the egg in the flask so that the candle is inside the flask. Move the egg into the opening of the flask.  Don't push it too far. Simply move the egg until it forms a “seal” with the flask (so no air could enter or escape the flask). 
  6. Hold the egg in that position.
  7. As the egg starts to move, let go of the egg.

*You will need to use a 500 mL flask for this experiment. Also, in order to get the eggs out, you have to break them apart inside the flask. So, it is messy!  

Prompt #1:

Watch as the discussion pushes their students to work through their understanding. Through summarizing and finding evidence in text, they clarify their own misconception and develop their own understanding!  

Prompt #2:  

Keep in mind for Prompt #2 that you will need to print the isobar map for students to refer to. Listen as these students again use this protocol to create their own understanding and clarify misconceptions.  

Closure: Is the Ghost gone?

5 minutes

To close, I ask a follow up question to the "Ghost Closer" demonstration and as a class, we go through the protocol to make a prediction. I say,  "Yesterday, I was practicing this lesson to make sure it would work and the door didn't open or close. Does that mean that I did something to get rid of the ghost?"  

By following the protocol, students should explain that the 'ghost' wasn't gone, the pressure outside was just the same as it was inside and thus air was not moving.